<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>03_BOM操作</title>
</head>
<body>
<button onclick="alert('警告框')">弹出警告框</button>
<button onclick="confirm('确认')">您确定要删除吗</button>
<button onclick="prompt('请输入会员卡号')">弹出输入框</button>
<script>
    console.log(parseInt(6.6));//6
    console.log(parseInt(6.1));//6
    console.log(parseInt(6));//6
    console.log(parseInt('hhh'));//NaN
    console.log(parseInt('12hh34h56'));//12
    //将参数转为小数
    console.log(parseFloat(5.6));//5.6
    console.log(parseFloat(5));//5
    console.log(parseFloat('hhh'));//NaN
    console.log(parseFloat('3.4hh3.3h3.1'));//3.4
    //判断参数是否非数字，数字得到false，非数字得到true
    console.log(isNaN('hhh'));
    console.log(isNaN(7));
    console.log(isNaN(7.7));
</script>
</body>
</html>